1. Field of the Invention
The present invention relates to an input device capable of enabling and disabling a sleep mode, and in particular, relates to an input device whose operability is not impaired when the sleep mode is disabled.
2. Description of the Related Art
Some input devices for game consoles, personal computers and the like can vary the outputs in an analog fashion in response to the pushing force.
An input device disclosed in Japanese Unexamined Patent Application Publication No. 2002-93274 includes an electrode provided on a substrate and a click rubber member composed of silicone or the like opposing the electrode. Pulsed electricity is supplied to the click rubber member. When a key top is pressed, the click rubber member comes into contact with the electrode to generate an output. When the click rubber member is further pressed to the electrode, the click rubber member is elastically deformed and the output is varied in response to the amount of deformation.
Some input devices can be put into a sleep mode to reduce power consumption when the input devices are left unoperated for a predetermined period.
In order to enable and disable the sleep mode in the above-described input device, the click rubber member needs to be separated from the electrode when the key top is not pressed. The sleep mode is enabled when the click rubber member does not come into contact with the electrode for a predetermined period, and is disabled when the key top is pressed to bring the click rubber member into contact with the electrode. However, this arrangement requires a predetermined pushing force before an output is generated after the key top is pressed. This causes a ‘dead zone’ which impairs the operability when the arrangement is applied to an input device whose output varies in an analog fashion in response to the pushing force.
Furthermore, since one circuit is used for detecting operations both in the sleep mode and in a normal operation mode, the circuitry and the control are disadvantageously complicated.